JPH0922111A - Pellicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent production of air path or air reservoir between a reticle and a frame and to decrease the sticking load on a pellicle to a glass substrate by forming the whole surface of an adhesive layer as a projecting face to stick the a reticle. SOLUTION: The adhesive layer of a pellicle is formed as a projecting face as a whole. Namely, for example, it is formed like half-cylinder or cylinder as shown in the Figure. In this case, for example, a half-cylindrical adhesive layer is formed on a reticle as shown in the figure, and because of the half- cylindrical shape, the adhesive layer hardly produces air reservoir compared to a conventional one and the adhesive layer can be adhered to the reticle under smaller pressure. When the adhesive is pressed, the layer is changed into a planer shape and can be to adhere to the reticle with high bearing pressure. To increase the adhesion area between the reticle and the adhesive layer, the adhesion pressure is increased. Thus, the adhesive area can be easily controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Substantially 500 used to prevent dust when manufacturing semiconductor devices such as SI and VLSI, or liquid crystal display panels.
The present invention relates to an antistatic pellicle in an exposure method using light of nm or less.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices such as LSIs and VLSIs or liquid crystal display panels, a semiconductor wafer or a liquid crystal master is irradiated with light to form a pattern. If dust adheres, the dust absorbs light or bends the light, so the transferred pattern will be deformed, the edges will be rough, and the white background will be stained black, In addition, there is a problem in that the quality, appearance, and the like are impaired, and the performance and manufacturing yield of semiconductor devices and liquid crystal display panels are reduced. For this reason, these operations are usually performed in a clean room, but it is difficult to always keep the exposure master clean in this clean room.Therefore, the exposure master light often passes through the surface of the exposure master for exposure to prevent dust. A method of attaching a pellicle to be used is used.

[0003] In this case, the dust does not directly adhere to the surface of the exposure master, but adheres to the pellicle. Therefore, if the focus is set on the pattern of the exposure master during lithography,
Dust on the pellicle is unrelated to the transfer, but this pellicle film usually consists of a transparent pellicle film made of nitrocellulose, cellulose acetate, etc. that passes light well over the pellicle frame made of aluminum, stainless steel, polyethylene, etc. A pellicle film is coated with a good solvent and air-dried for adhesion (see JP-A-58-219023) or an adhesive such as an acrylic resin or an epoxy resin (US Pat. No. 4,861,402, Japanese Patent Publication No. 63-27,707), and further, for the purpose of protecting the adhesive layer made of polybutene resin, polyvinyl acetate resin, acrylic resin, etc., and the adhesive layer in order to be mounted on the exposure master plate under the pellicle frame. It is composed of a release layer (separator).

[0004]

In this pellicle composition, the adhesive layer is important because it is necessary to attach the pellicle to the reticle as a glass substrate before using the pellicle. To be done. However, when the pellicle is attached to the reticle, there may be a gap (hereinafter referred to as an air path) or an air pool between the reticle and the adhesive. There is a risk that it will adhere to the upper part, and if there is an air pocket there, the air pocket will increase over time, and this may eventually become an air path.

Therefore, under the present circumstances, when the pellicle is pressure-bonded to the reticle, it is necessary to apply a load of 30 kg or more to the entire surface of the pellicle, which may cause a trouble that the expensive reticle is broken. Therefore,
In this regard, attempts have been made to soften the pressure-sensitive adhesive to reduce the pressure applied to the pellicle, but if this is made soft enough to satisfy the bonding conditions, then the time of the pellicle that has been bonded will be reduced. Since the shape stability in (1) becomes insufficient, the examination for this is a problem.

[0006]

The present invention relates to a pellicle that solves the above disadvantages and problems. It has an adhesive layer of a pellicle for sticking a pellicle to a glass substrate, and the entire surface thereof is a convex curved surface. Is formed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Usually, in order to attach the pellicle to the reticle at a uniform height, the adhesive layer of the pellicle is finished so as to be as flat as possible by eliminating the unevenness of the adhesive layer surface as shown in FIG. However, in this case, since it is flat, there is a disadvantage that an air pocket is likely to be generated when it is attached to the reticle. In fact, if the adhesive layer of this pellicle is made flat as shown in FIG. 3, an air pocket will be generated here when sticking to the reticle because the contact area with the reticle is large, and as shown in FIG. Even if pressure is applied to this, it does not stick to the whole under a load of 10 kg, and in this case it was necessary to increase this load to 30 kg which could damage the reticle.

The present invention has solved such disadvantages, as described above, in which the adhesive layer of the pellicle has a convex curved surface over the entire surface thereof, as shown in FIG. 1, for example. It is a fish-bowl type or a bale type (not shown). As an example of this, a kamaboko-shaped adhesive layer is placed on the reticle as shown in FIG. 1, but this is a kamaboko-shaped adhesive layer, so air pockets are generated compared to the conventional one in FIG. It was difficult to do this, and it was found that this can stick the adhesive layer and the reticle with a small pressure, and when this is pressed, it becomes a flat plate as shown in FIG. 2 and adheres to the reticle with a high surface pressure, It was confirmed that when the adhesive is applied, and in this case, when the adhesive surfaces of the reticle and the adhesive layer are desired to be increased, the pressure can be arbitrarily controlled by increasing the pressure force.

When the pressure-sensitive adhesive layer of the kamaboko type is attached to the reticle by applying pressure, the original shape of the kamaboko type becomes flat due to the pressure, but in this case, no air pool is generated and no air path is possible. The load of this pressurization may be about 10 kg. Although the thickness of this product is 90% or less of that before attachment, it becomes flat and has a large adhesive force, so that it has a practically sufficient adhesive force.

However, during this pressure bonding, the pressure in the area blocked by the pellicle and the glass substrate becomes high, and the pellicle film is likely to swell unless this pressure is released.
In order to prevent the pellicle film from swelling, it is preferable to provide a ventilation hole for adjusting the atmospheric pressure in the pellicle frame. Furthermore, in order to prevent particles from being mixed into the ventilation hole from the outside, there is a filter here. Should be provided.

[0011]

Next, examples of the present invention and comparative examples will be described. Example The surface is anodized, the height is 6.3 mm, the outer circumference of the end face is 120 mm square, the inner circumference is 110 mm square, and the center of one side is 0.5 mmφ
An aluminum frame with a through hole was prepared. Then, a silicone adhesive KR-120 [trade name of Shin-Etsu Chemical Co., Ltd.] is applied to the lower end surface so as to form a kamaboko shape with a thickness of 0.6 mm and cured at 120 ° C. for 30 minutes, and this frame is further cured. Amorphous fluoropolymer CYTOP CTX-A type [Product name of Asahi Glass Co., Ltd.]
It was applied to have a thickness of 0.1 mm.

The inner surface of this frame is coated with silicone adhesive KR-120 (previously described) to a thickness of 0.05 mm (except for a through hole of 0.5 mmφ), and further 0.5 mmφ. The hole diameter is 0.5 so that the through hole is blocked.
A filter made of polytetrafluoroethylene (PTFE) with a size of 10 μm and a size of 10 × 5 mm is installed, while an amorphous fluoropolymer, CYTOP CTX-S type [trade name of Asahi Glass Co., Ltd.] is 1.62. A μm thin film was formed, and this was heat-sealed to this frame at 108 ° C.

Next, the pellicle thus finished was placed on the reticle, and a load of 10 kg was applied to the upper surface of the pellicle frame to attach the pellicle to the reticle.
In this case, the thickness of the silicone adhesive KR120 (described above) was 0.5 mm, and no gap such as an air path or an air pool was found between the reticle and the frame, so the pellicle was attached immediately after applying a load of 10 kg. The bulge of this pellicle returned after 10 minutes.

Comparative Example 1 A frame similar to that of the example was prepared, and a silicone adhesive KR-120 (described above) was applied to the lower end surface of the frame so as to form a plate having a thickness of 0.3 mm, and the temperature was 120 ° C. for 30 minutes. Cure for a minute, and then add Cytop CT to the top surface of the frame.
The XA type (described above) was applied so that the thickness would be 0.1 mm. The inner surface of this frame is coated with silicone adhesive KR-120 (described above) to a thickness of 0.05 mm (excluding 0.5 mmφ through holes).
Furthermore, so as to block the 0.5 mmφ through hole, the hole diameter is 0.5 μm,
A filter made of PTFE with a size of 10 mm × 5 mm is provided, while a 1.62 μm thin film is formed on the above-mentioned Cytop CTX-S type (described above) and heat-sealed onto this frame at 108 ° C. did.

Then, the pellicle thus finished is placed on the reticle, and 10 kg is put on the upper end surface of the pellicle frame.
When the pellicle was attached to the reticle by applying the load of., In this case, a gap such as an air path was seen between the reticle and the frame, so the pellicle and reticle did not stick and the load was increased until the air path disappeared. When I did this, the whole thing finally stuck at 30 kg because the load could damage the reticle.

Comparative Example 2 An aluminum frame having a height of 6.3 mm, an outer circumference of an end face of 120 mm square and an inner circumference of 110 mm square (without a through hole of 0.5 mm) was prepared. Then, a silicone adhesive KR-120 (described above) was applied to the lower end surface so as to form a bale shape having a thickness of 0.6 mm, cured at 120 ° C. for 30 minutes, and further, the above-mentioned size was applied to the upper end surface of the frame. Top CTX-A type (described above) was applied to a thickness of 0.1 mm. The inner surface of this frame is coated with a silicone adhesive, KR-120 (previously described) to a thickness of 0.05 mm, while 1.62 μm for Cytop CTX-S type (previously described). Was formed into a thin film and heat-sealed to a frame at 108 ° C.

Next, the pellicle thus finished is placed on the reticle, and 10 kg is put on the upper end surface of the pellicle frame.
When the pellicle and the reticle were attached by applying a load of, the adhesive was in the shape of a bale in this case, so no gap such as an air path was seen between the reticle and the frame,
Although this adhered with a load of 10 kg, the bulge of the pellicle film generated immediately after the load of 10 kg was not restored.

[0018]

The present invention relates to a pellicle,
This is an adhesive layer for sticking a reticle, whose entire surface forms a convex curved surface. According to this, it is possible to prevent the occurrence of air paths, air pools, etc. between the reticle and the frame. Therefore, the pellicle can be attached to the glass substrate with a small load, and therefore the substrate can be prevented from being damaged when the pellicle is attached.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a pellicle according to an example of the present invention in which an adhesive layer has a kamaboko shape.

FIG. 2 is a vertical sectional view of the pellicle when a pressure load is applied to the pellicle of FIG.

FIG. 3 is a vertical cross-sectional view of a known pellicle having a plate-shaped adhesive layer.

FIG. 4 is a vertical sectional view of the pellicle when a pressure load is applied to the pellicle of FIG.

Claims (5)

[Claims] 1. A pellicle characterized in that an adhesive layer of the pellicle for attaching the pellicle to a glass substrate is formed so that the entire surface thereof forms a convex curved surface. 2. The pellicle according to claim 1, wherein the adhesive layer has a kamaboko shape. 3. The pellicle according to claim 1, wherein the thickness of the adhesive layer when attached to a glass substrate is 90% or less of that before attachment. 4. The pellicle according to claim 1, wherein the pellicle frame is provided with ventilation holes for adjusting atmospheric pressure. 5. The pellicle according to claim 4, wherein the ventilation hole is provided with a filter for preventing particle contamination.